RBC Disorders Flashcards
WHO definition of anemia
Hb < 13 g/dL in men
Hb < 12 g/dL in women
Hb and Hct are important to consider in anemic pts because certain conditions may yield low Hb levels with a normal Hct — what is an example of a condition that does this?
Thalassemia
When Hb levels do not approximate 1/3 of Hct, what are some other lab findings to check for?
High leukocyte counts Lipemia Precipitating monoclonal proteins Cold agglutinins Hyperglycemia
Normocytic anemias with primarily extravascular hemolysis
Hereditary spherocytosis
Sickle cell anemia
Hemoglobin C
Normocytic anemias with predominantly intravascular hemolysis
Paroxysmal nocturnal hemoglobinuria
G6PD deficiency
Immune hemolytic anemia
Microangiopathic hemolytic anemia
Anemias due to underproduction
Aplastic anemia (drugs, chemicals, viral infxn, autoimmune damage)
Myelophthisic process
Causes of microcytic hypochromic anemia
Iron deficiency
Inflammatory block to iron utilization
Thalassemia
Sideroblastic
Causes of macrocytic anemia
Stress erythropoiesis (accompanied by high retic count)
Nonmegaloblastic causes = liver disease, asplenia, hyposplenia, hypothyroid
Megaloblastic causes = B12 deficiency, folate deficiency, certain drugs, alcohol myelodysplasia
In what types of anemia would you see hyperchromic cells?
Disorders that lead to increased Hb per RBC and/or Hct, implying loss of RBC membrane in relation to RBC volume — occurs in HEMOLYTIC anemias and certain HEMOGLOBINOPATHIES
What lab is used to determine whether bone marrow response to anemia is adequate?
Reticulocyte count
Anemia in the setting of appropriately increased retic counts (>100,000/microliter) almost always reflect what cause(s) of the anemia?
Erythrocyte loss (bleeding, hemolysis)
Also occurs as a response to therapy (iron, folate, B12
Anemia in the setting of low retic count) indicates what cause(s) of the anemia?
Erythrocyte underproduction d/t deficient erythropoietin — includes the nutritional deficiencies (B12, folate, iron)
Leading cause, symptoms, and peripheral blood findings in aplastic anemia
Leading cause = autoimmune (other cause is drug-induced marrow suppression)
Symptoms occur d/t underlying pancytopenia — fatigue, dyspnea, bleeding, infection
PB shows anemia, thrombocytopenia, leukopenia
Management of aplastic anemia
Allogeneic HCT in pts <40 and otherwise healthy
Pts not eligible should receive immunosuppressive therapy with antithymocyte globulin and cyclosporin
PB smear findings w/iron deficiency anemia
Hypochromia (increased central pallor)
Anisocytosis
Poikilocytosis
Lab test most useful for dx of iron deficiency anemia
Serum ferritin
[decreased serum ferritin, increased TIBC, decreased serum iron, decreased %sat, increased FEP]